To this end, it is known in the art to use Zr alloys which are said to be “ternary” or “quaternary” according to the number of main alloying elements they contain. Ternary alloys contain, in addition to Zr, significant amounts of Nb on the one hand, Fe and possibly Cr and/or V on the other hand. Quaternary alloys contain, in addition, a significant amount of Sn. Other elements than the ones which have been cited may be present, either as mere impurities which, in some instances, must be kept within strict limits through a careful choice of the raw materials from which the alloy is made, or as deliberate additions which, though they may be limited to small amounts, have a significant influence on the mechanical and/or chemical properties of the alloy. Among these elements, Ni, O, C, Si, S can be cited.
These alloys may be used in a stress-relieved condition, i.e. with less than about 10% of recrystallized grains, in a recrystallized condition also named completely or fully recrystallized condition, i.e. with more than about 90% of recrystallized grains or in a partially recrystallized condition, i.e. with about 10% to about 90% of recrystallized grains.